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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  package org.apache.http.client.entity;
28  
29  /*
30   * ====================================================================
31   * Licensed to the Apache Software Foundation (ASF) under one
32   * or more contributor license agreements.  See the NOTICE file
33   * distributed with this work for additional information
34   * regarding copyright ownership.  The ASF licenses this file
35   * to you under the Apache License, Version 2.0 (the
36   * "License"); you may not use this file except in compliance
37   * with the License.  You may obtain a copy of the License at
38   *
39   *   http://www.apache.org/licenses/LICENSE-2.0
40   *
41   * Unless required by applicable law or agreed to in writing,
42   * software distributed under the License is distributed on an
43   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
44   * KIND, either express or implied.  See the License for the
45   * specific language governing permissions and limitations
46   * under the License.
47   * ====================================================================
48   *
49   * This software consists of voluntary contributions made by many
50   * individuals on behalf of the Apache Software Foundation.  For more
51   * information on the Apache Software Foundation, please see
52   * <http://www.apache.org/>.
53   *
54   */
55  
56  import java.io.IOException;
57  import java.io.InputStream;
58  import java.io.OutputStream;
59  import java.util.zip.GZIPOutputStream;
60  
61  import org.apache.http.Header;
62  import org.apache.http.HttpEntity;
63  import org.apache.http.entity.HttpEntityWrapper;
64  import org.apache.http.message.BasicHeader;
65  import org.apache.http.protocol.HTTP;
66  import org.apache.http.util.Args;
67  
68  /**
69   * Wrapping entity that compresses content when {@link #writeTo writing}.
70   *
71   *
72   * @since 4.0
73   */
74  public class GzipCompressingEntity extends HttpEntityWrapper {
75  
76      private static final String GZIP_CODEC = "gzip";
77  
78      public GzipCompressingEntity(final HttpEntity entity) {
79          super(entity);
80      }
81  
82      @Override
83      public Header getContentEncoding() {
84          return new BasicHeader(HTTP.CONTENT_ENCODING, GZIP_CODEC);
85      }
86  
87      @Override
88      public long getContentLength() {
89          return -1;
90      }
91  
92      @Override
93      public boolean isChunked() {
94          // force content chunking
95          return true;
96      }
97  
98      @Override
99      public InputStream getContent() throws IOException {
100         throw new UnsupportedOperationException();
101     }
102 
103     @Override
104     public void writeTo(final OutputStream outstream) throws IOException {
105         Args.notNull(outstream, "Output stream");
106         final GZIPOutputStream gzip = new GZIPOutputStream(outstream);
107         wrappedEntity.writeTo(gzip);
108         // Only close output stream if the wrapped entity has been
109         // successfully written out
110         gzip.close();
111     }
112 
113 }